Aprillia Mx 125 Issue.

Hey Guys,
I have a problem with my mx 125 (07 modle) not hitting the powerband.

I have had the bike 3 days and just managed to get on it yesterday, it was all working fine hitting powerband and was flying. Then a car pulled out on me and I had to brake hard causing my bike to cut out (maybe I didn't pull in the clutch). Anyhow I then kicked it again (first time) and started on my travels, but then when it should be hitting powerband it was coughing and slugging. I looked at the digital clock and it was telling me to change gear (the up and down arrows), so i did and it give a little boost as it dose when changing gear. So i was going 30mph in 4/5th gear.

I have no Idea what so ever what could be wrong.

Thanks,
Matty